Recording, processing and reproduction of images grows with an increasing demand for information and their clear graphic visualization. Electronic image processing also involves processing of images taken by cameras, scanning systems and sensors in the visible light spectrum as well as in other sections of the electromagnetic spectrum such as the infrared, the radio frequency and the X-ray frequency range. After electronic processing, many images are reproduced either as individual images or as moving images on an image reproduction screen such as a display for presenting the information to the eye.
There are special image contents easier recognizable by electronic image processing using, for example, local frequency filtering, margin sharpness increasing, image data compression, image correlation, dynamic reductions and false color-coding. On the other hand, other techniques are concerned with the superposition or subtraction of auxiliary images taken from different spectral ranges or with the superimposing of stored plans, maps, and drawings onto the original image.
By applying image processing, the information content of the actual, direct image can be intentionally increased or reduced. Image processing is used in a wide range from increasing the image contrast to blending-in of additional information, marking of details, and highlighting dangers. In many of these applications, it is disadvantageous that the electronic camera is a “second eye system” separate from the human eye. This disadvantage is due to the fact that the images are seen from another recording location and that additionally, the pictures on the image screen are presented at another observation location than the eye. Thus, the human eye must constantly change between the direct observation and the indirect observation while taking into account different observation angles, different image details, and different size ratios which leads to physical impairments and delays when decisions must be made.
These problems may be solved by the “head-up-display” (HUD) technique used in the piloting of combat aircraft, in that important information such as instrument displays and target data are inserted or fade-in into the open spectacles of the pilot's helmet and thus into the visual field of the pilot. This technique is also used experimentally in the automobile industry for displaying of instrument readings on the windshield so that the driver is not distracted from viewing the road by viewing the instrument panel.
The “virtual reality” or “cyber space” techniques use closed spectacles (i.e. glasses) where the outside view is blocked and three-dimensional full images are projected into the eye with virtual reality. These virtual reality images are then modified in response to body motions such as locomotion, movement of an arm, a finger, or head and eye movements.
There are other HUD techniques and image detection and projection techniques described in the PCT Application PCT/EP97/04188 (published as WO98/05992) and U.S. Pat. No. 6,227,667. The apparatus described in these documents capture (or detect) the retinal reflex image and also enable a superimposition of supplementary images in the eye.
There is still a need for an information system capable of providing interactive data view and command applications for use in various environments.